Lifting-jack.



H. H. HUFFMAN.

LIFTING JACK.

APPLHIATION HLED SEPT. 20. 1916.

Patented J an. 23, 1917,

HenryHHuffman A n HENRY II. HUFFMAN, OF COLUMBUS, ()HIO.

LIFTING-JACK.

Specification of Letters Patent.

Patented Jan. 23, 1917.

Application filed September 20, 1916. Serial Ito. 121,177.

To all "whom it may concern Be it known that I, Henry H. ITUFFMAN,acitizon of the United States, residing at Columbus, in the county ofFranklin and State of Ohio, have invented a certain new and usefulImprovement in Lifting-Jacks,

of which the following is a specification.

The principal object of this invention is to provide a lifting jack ofsimple and economical construction in which the lifting bar can belowered either slowly or quickly according to requirements in use.

The invention is embodied in the example herein shown and particularlyset forth, the features of novelty being finally claimed.

In the accompanying drawing, Figure 1 is a view in side elevation with aportion of the base broken away to show the position of the operatingbar in the ordinary lifting operation. Fig. 2 is similar View showingone position of the parts when the lifting bar is being lowered step bystep. Fig. 3 is a similar but fractional view showing the position ofthe parts when the lifting bar has been lowered a tooth in the loweringop eration. Fig. i is a similar but fractional view showing the positionof the parts when the lifting bar has been quickly lowered.

The jack includes a base or stand 5 having pivoted to its front portiona pawl 6 to engage the teeth of the-lifting bar 7. As usual, the liftingbar 7 slides vertically in a suitable socket in the base, said bar beingprovided with a toothed edge 8 and head 9 that, if desired, may beswiveled to the upper end of the ban The lifting bar also has projectingfrom its edge a supplemental load rest 10.

For its proper operation the structure includes an operating bar 11having at one end two teeth 12, 12 extending substantially parallel toeach other and in the instance shown in a direction parallel to thelength of the operating bar and at the other end a single tooth 13standing at an angle to the said length. Near each end of the operatingbar is a pair of trunnions like that shown at 14 to rest in bearings orfulcrums 15 in wings 16 at the upper portion of the forward edge of thebase. These wings have parallel openings 17 leading to the bearings sothat the trunnions at either end of the operating bar can be insertedand moved therein according to the end of the operating bar to be usedin working the lifting bar.

The pawl 6 has a weighted arm 18 extending rearward tending to hold theend of the pawl inward toward the toothed or racked edge of the liftingbar. Said pawl also has a forwardly extending finger 19 adapted to bedepressed bf the operating bar or by a projection 20 thereon accordingto which end is used to operate the lifting bar. The inner portion ofthefinger 19 has a depression, as at 19. The projection 20 of the operatingbar has a hole in which is loosely fitted a pin 91. Said pin can besuitably headed where necessary to prevent it from dropping out of thehole.

The lifting bar 7 can be raised with either end of the operating bar.lVhen that end of the operating bar having two teeth is used to raisethe lifting bar the other end of the lifting bar should be raised andthe upper tooth inserted under the proper tooth as shown in full linesFig. 1 with the projection 20 on the operating bar uppermost. lVhen thelifting bar is to be slowly lowered the operating bar should be insertedin a nearly horizontal position with the projection 20 lowermost so asto embrace the proper tooth. Then by depressing the operating bar untilthe pin 21 enters the depression 19 the pawl is actuated to fetch itinto position, as shown in F 2, to permit a tooth or teeth of thelifting bar to pass the end of the pawl, as shown in Fig. 3. In thisoperation the pin 21 retains the pawl in removed position suflicientlylong to'permit the lowering of the lifting bar one or more teeth with astep by step mo ement. To secure a quick lowering of the lifting barthat end of the operating lever bearing the single tooth is employed.This end is inserted in any posi tion where it can take a tooth and thenthe other end depressed until the pawl and said tooth are removed fromengagement with the lifting bar whereupon the lifting bar willcompletely fall under its load, as shown in Fig. 4;.

Vhat I claim is:

1. A lifting jack comprising, in combina tion, a base. a lifting barhaving a toothed edge, a pawl and means for causing the same to beautomatically engaged with said toothed edge. an operating barconstructed to engage said toothed edge to raise and lower the liftingbar and to directly actuate the pawl to remove the same from engagementwith said lifting bar, and an automatically sliding device on theoperating bar for engaging said pawl and holding the pawl disengagedfrom the lifting bar when the operating bar is moved to lower thelifting bar.

A lifting jack comprising, in combination, a base, a lifting bar havinga toothed ed e, a pawl and means for causing the same to beautomatically engaged with said toothed edge, said pawl also having afinger with a depression therein, an operating bar eonstrlmted to engagesaid toothed edge to raise and lower the lifting bar and to directlyactuate the pawl to remove the same from engagement with said liftingbar, and

a sliding pin on the operating bar to drop into said depression. to holdsaid pawl disengaged from the lifting bar when the operating bar ismoved to lower the lifting bar.

A lifting jack comprisin in combination, a base, a lifting bar having atoothed edge, a pawl pivoted in the base to engage said toothed edge,means for causing the same to be automatically engaged therewith, and anoperating bar having trunnions to fulcrum in the base above the fulcrumof the pawl and having at the same end a single rigid tooth. to engage atooth of the lifting bar, the other portion of said bar forming a handleand. constructed to engage the pawl, when depressed, to release the samefrom engagement with the lifting bar, said tooth standing, when the baris in operative position, at an upward inclination to the axis of theoperating bar, whereby the said tooth may be disengaged from the liftingbar and the said handle subsequently depressed to Contact with the pawlto release the same from the lifting bar thereby permitting the liftingbar to fall.

HENRY H. HUFFMAN.

Gonies of this patent may be obtained for five cents each by addressingthe Commissioner of Eatents, Washington, D. G.

